A method of providing signal synchronization for a radio access network may include transmitting a first carrier including synchronization signals on a first frequency from the radio access network. Information relating the first carrier on the first frequency with a second carrier on a second frequency may be transmitted from the radio access network, with this information being intended to be used in synchronization by a wireless terminal upon addition of the second carrier. More particularly, the first and second frequencies may be different. A command to add the second carrier as a downlink for transmissions may be transmitted to the wireless terminal. Related network nodes and wireless terminals are also discussed.